Electrical connector



ELECTRICAL CONNECTOR 2 Sheets-Sheet 1 Original Filed Jan. 19, 1965 EDGARA. BONGORT m 5 0m K WA v T G L N U L E 6 m w 2 H 7/! ///////////W//////lf/{l/l/f/l/ll/l/ il/ll/l/ I/l/l/l/ Ill/l/ll/ f 2 K0 3 2 8 8 2 4 3 5 5 6w 4 O 4 3L l III III mtff 11- L w. T. AKIN ET AL 3,475,719

ELECTRICAL CONNECTOR Oct. 28, 1969 2 Sheets-Shet 2 Iriginal Filed Jan.19, 1.965

ii vd hv I T mR w N 0 TB GA a A G D WE United States Patent 3,475,719ELECTRICAL CONNECTOR Welling T. Akin, Birmingham, and Edgar A. Bongort,

Southfield, Mich., assignors to B/W Controller Corporation, Birmingham,Mich., a corporation of Michigan Original application Jan. 19, 1965,Ser. No. 426,522, now Patent No. 3,313,902, dated Apr. 11, 1967. Dividedand this application Mar. 23, 1967, Ser. No. 625,522 Int. Cl. Hillr13/50, 9/08 US. Cl. 339-182 1 Claim ABSTRACT OF THE DISCLOSURE Thisdisclosure relates to a socket type electrical connector for effectingconnection between a plurality of electric wires and a coaxialarrangement of conducting surfaces such as the exposed ends of anelectrode assembly useful in liquid level control devices.

In our copending application, Ser. No. 426,522 filed Jan. 19, 1965, nowUS. Patent 3,313,902 issued Apr. 11, 1967 of which this application is adivision, we disclose an electrode assembly useful in liquid levelcontrol devices, and an electrical connector of the socket type which isadapted to be pressed over the projecting end of the electrode assemblyto effect connections of electric leads therewith. The connector is ofsuch construction that it tightly grips the end of the electrodeassembly to avoid accidental dislodgment, and when in place on theelectrode assembly substantially prevents the entry of moisture orforeign matter into the electrical connection.

This disclosure shows a female electrical connector for connecting aplurality of conductors to a male member having a plurality of axiallyspaced conductive end portions in which the connector is molded ofresilient electrically non-conductive material in which there are aplurality of electrically conductive helical wire coils embedded in theconnector for limited radial expansion upon mounting of the connector onthe male member to engage the electrically conductive portions thereofand effect electrical connection between the conductors and saidportions of the male member.

In the drawings:

FIGURE 1 is a vertical sectional view of a liquid carbonating tankshowing an electrode assembly embodying the invention mounted thereinand comprising an electrode unit and our improved electrical connectormounted thereon;

FIGURE 2 is a side elevation, partly in section, of the electrodeassembly and the electrical connector shown in FIGURE 1;

FIGURE 3 is a cross-sectional view taken along line 33 of FIGURE 1;

FIGURE 4 is an exploded view, partly in section of a slip connector forthe electrodes showing clip means for securing the connector to anelectric conductor; and

FIGURE 5 is a perspective view of the parts of FIG- URE 4 shown inassembled condition.

In FIGURE 1 there is shown a liquid carbonating tank 20 having acylindrical side wall 22 and a curved bottom wall 24 integrally securedtogether as by welding. The top of the tank is hermetically closed by aclosure plate 26 havin apertures through which project the partsdescribed herebelow.

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A liquid inlet fitting 28 having a check valve therein is threadedlyreceived in a suitable aperture in plate 26, and includes an inletpassage 30 opening into the tank 20 and a liquid supply pipe 32connected to a pump or the like (not shown) to supply water or otherliquid to the tank 20. There is also a second fitting (not shown)threaded into plate 26 for the introduction of carbonic gas underpressure. Such may be identical to fitting 28 and adapted for connectionthrough suitable pressure control devices to a cylinder of liquefiedcarbon dioxide in a well-known manner. Plate 26 also exhibits anunthreaded aperture 34 within which there is secured as by welding aliquid outlet fitting 36, the upper end of which is threaded as at 37for connection to a pipe or hose. A liquid discharge tube 38 projectsinto the tank 20 from fitting 36 and terminates in an inwardly curvedportion 40 having its open end adjacent the bottom tank wall 24approximately at the centerline of the tank. Those parts of thecarbonator described hereinabove are conventional in the art and form nopart of the instant invention.

An improved electrode assembly embodying the invention is indicatedgenerally by the numeral 42 in FIG- URES 1 and 2, and comprises anelectrode unit and an electrical connector 80. The electrode unitcomprises telescopically connected inner and outer electrodes 44 and 46electrically insulated from each other by an intervening dielectricsleeve 50, with opposite ends of the electrodes being exposed forpurposes hereinafter explained. A coupling or bushing 54 is telescopedover the electrode unit with an intervening dielectric sleeve 52separating the outer electrode 46 from the coupling. Improved sealingmeans are provided for sealing the electrodes, sleeves and couplingagainst leakage of fluid pressure axially thereof. A cylindrical ortubular splash shield 66 may be provided which is supported on theelectrode assembly and defines a chamber about the exposed end 46b ofthe outer electrode to prevent false liquid level sensing. The electrodeunit is shown disposed vertically in the tank 20. Electrode 44 projectsbelow electrode 46, and is provided with a threaded lower end to receivean enlarged tip 48 of carbon or graphite in accordance with commonpractice in the art.

More specifically there is interposed between the electrode rod 44 andthe electrode tube 46 an insulating sleeve or tube 50 made of a suitabledeformable dielectric material such as plastic or the like, polyvinylchloride being suitable for this purpose, the opposite end portions ofwhich project beyond the ends of tube 46 and grippingly encircle the rod44, leaving however, the upper end 44a of the rod and the carbon tip 48exposed, as shown in FIGURE 2. A second insulating sleeve or tube 52 ofthe same material as sleeve 50 snugly encircles electrode tube 46terminating intermediate opposite ends of the tube to leave the endsexposed, as at 46a and 46b. An axially bored fitting or coupling member54 is received over sleeve 52, and is provided with an externallythreaded length 56 for reception within a threaded aperture 58 in theclosure plate 26 of tank 20.

As shown in FIGURES 2 and 9, inner electrode rod 44 exhibits acircumferential groove 60 spaced from the outer end thereof. Anelastomeric O-ring 61 encircles tube 50 radially opposite such groove.Outer electrode tube 46 has its upper ned counterbored as at 47 to forma lip 62 which is inwardly rolled or swaged radially opposite the groove60 on the rod to compress the O-ring and force the sleeve or tube 50into the groove 60 to the position shown in FIGURE 2. The contraction ofthe O-ring by the swaging or rolling of the lip places'the O-ring undercompression and the inward circumferential force of the O-ring under theinfluence of the lip 62 displaces the tube 50 forcibly into groove 60,forming a fluid-tight seal between the rod 44 and tube 46 and inaddition preventing relative axial movement therebetween.

The upper end of bushing 54 is counterbored similar to that of electrodetube 46 as shown in FIGURE 9. A circumferential groove 64 is machined inelectrode 46 spaced from the upper end thereof. An elastomeric O- ring65 is slipped over tube or sleeve 52 and positioned radially oppositegroove 64. The lip 54a at the upper end of the fitting is then swaged orrolled over the O-ring to compress it radially and cause it to contractabout insulating sleeve 52, in turn forcing the sleeve into the groove64 to effect a fluid-tight seal between the fitting 54 and the outerelectrode tube 46. This squeezing of the O-ring and sleeve 52 also locksthe electrode unit in the fitting against displacement.

The elastomer selected for the manufacture of the O-rings 61 and 65 maybe that normally used for fluid pressure sealing O-rings. In any eventit should be of suflicient elasticity so that it will continuously urgethe underlying sleeve forcibly into the respective grooves 60 and 64despite tendency of the underlying sleeve to thin out slightly with coldflow. It will be noted that the O-rings are entrapped on three sides bythe overlying swaged lip. The end of the lip is disposed adjacent thesleeve immediately above the O-ring to prevent extrusion of the O-ring.

In swaging or rolling the lip 62 and the lip 54a the respective O-ringsare contracted about the sleeve as aforesaid. This contraction may arisefrom either or both of two actions of the lip. As shown in FIGURE 9 theO-ring is somewhat flattened in cross section prior to swaging of thelip. When the lip is swaged or flared over an axial loading is imposedon the O-ring tending to increase its cross-sectional radial dimensionand forcing its inside surface against the sleeve to in turn press thesleeve tightly into the groove. This axial compression of the O-ringtherefore serves to load the O-ring and contribute to the sealingaction. During the rolling or swaging of the overlying circumferentiallip the ring is also radially compressed and this too contributes toloading of the ring and establishment of the seal.

The electrode assembly 42 functions to control the level of liquidwithin tank 20. As stated above, a pump is provided to pump water orother liquid into the tank through passage 30 in fitting 28. When theliquid level in tank 20 falls below the lower end 48 of electrode 44,the pump is started to supply water to the tank. When the level of thewater in the tank reaches the bottom of the upper electrode 46 the pumpis automatically stopped. Thus the liquid level in tank 20 is maintainedbetween the lower ends of the two electrodes 44 and 46.

In a carbonator of the character shown, the liquid is delivered to thetank through passage 30 in a jet stream under pressure, and the carbondioxide is also delivered under pressure, causing vigorous agitation ofthe liquid in the tank. As the liquid may splash against the lower endof electrode 46 when the actual level is much lower, giving a falsereading and thus stopping the pump, the electrode 46 is provided with atubular shield 66 having a lower skirt 68 spaced from the electrode andextending downwardly therebeyond as shown in FIGURE 2. Shield 66 isprovided with a vent hole 70 on opposite sides thereof. The upper end ofthe shield is inwardly tapered as at 72 for slidable reception betweentube 46 and sleeve 52 to be gripped therebetween, with a head 74assisting to hold the parts assembled. The lower end of sleeve 52 abutsagainst a shoulder 76 on the shield, which serves as a stop to preventthe shield from being improperly positioned. When thus assembled theliquid must rise in the shield 66 to contact the electrode tube 46,insuring against agitated liquid splashing up on the electrode to stopthe pump prematurely.

The electrode assembly 42 is coupled to an electrical control devicesuch as a relay (not shown) through a cable 78 which is releasablycoupled to the upper ends of the electrodes 44 and 46 and coupling 54 bymeans of the receptacle 80 shown in FIGURE 2. The receptacle 80 includesa cap or connector body 82 of molded plastic material such as polyvinylchloride or the like, and a plurality of electrically conductive slipconnectors 84, 86 and 88 embedded in the plastic. Each of these slipconnectors is in the form of a helical wire coil which is secured to arespective end of one of the conductors 90, 92 and 94 of cable 78 by aclip 96 as shown most clearly in FIGS. 4 and 5.

Each slip connector, such as the connector 84 of FIG- URE 4, is formedwith a projecting end portion 98 for insertion into the clip 96, whichis suitably formed of sheet metal or the like to accommodate theconnector end and the wire 90. Once the connector end 98 and wire endare inserted into the passages in the clip 96, the clip is crimped aboutthe wires as shown in FIGURE 5 to provide a secure connectiontherebetween. In making the receptacle 80, the slip connectors 84, 86and 88 are first connected to the wires 90, 92 and 94 respectively bythe crimp connectors 96, and the slip connectors then mounted on a dummycore pin similar in dimension to the upper end of the electrode assembly42, and the plastic material molded about the connectors and wires toform the cap 82. When the plastic has cured, the dummy core pin isremoved, leaving a stepped cylindrical cavity therein correspondingsubstantially to the configuration of the upper end of electrodeassembly 42. Preferably the slip connectors are placed under slighttension, so that upon completion of the receptacle they will contract toan inside diameter slightly less than the outside diameter of the upperends of the electrode rod 44, the electrode tube 46 and the coupling 54.Thus when the electrode assembly 42 is inserted into the receptacle 80,the connectors 84, 86 and 88 will releasably grip the respectiveportions of the electrode assembly, preventing accidental disengagement.In addition to providing a convenient releasable connection between theelectrode assembly 42 and the electrical cable 78, the receptacle 80 maybe positioned on the electrodes in any desired position of rotation, ormay be rotated while coupled to the electrodes.

The electrically conductive wall 22 of tank 20, coupling 54, slipconnector 88 and wire 94 provide a path for the flow of electricitywhich is common to both of the electrode circuits for controlling thepump supplying water or other liquid to the tank. One circuit includeselectrode tip 48, electrode 44, connector 84 and conductor 90. Thesecond circuit includes electrode 46, connector 86, and conductor 92. Asthe liquid in the tank is electrically conductive, when its level fallsbelow tip 48, the electrical connection between the tip and tank wall 22is broken, operating a suitable control to start the pump. Also, whenthe liquid rises to contact the lower end of electrode 46, a circuit iscompleted to a control operable to stop the pump. Thus the liquid levelin the tank is maintained between limits determined by the positions ofthe electrode tip 48 and the lower end of electrode tube 46.

What is claimed is:

1. A female electrical connector for engagement with a male memberhaving a plurality of axially spaced electrically conductive endportions, comprising: a connector body molded of resilient electricallynon-conductive material having a hollow cylindrical portion openingthrough one face of the body and adapted to releasably gn'ppingly engagethe projecting end portions of said male member; a plurality ofelectrically conductive helical wire coils embedded in said connectorbody for limited radial expansion and encircling said cylindricalportion in axially spaced-apart relation with the inner surfaces of eachcoil exposed to said opening in the body, each helical wire coilexhibiting an end portion projecting away from said helical coil; and anelectrical cable defining a plurality of insulated conductors extendingthrough a face of said connector body remote from said cylindricalportion with each conductor having an exposed end portion; meanspermanently electrically connecting the exposed end portion of one ofsaid wire coils with one of said exposed ends of said conductors, saidmolded connector body incapsulating said connected end portions to forman hermetically sealed structure; and each of said helical wire coilsbeing resistingly expandible to releasably grippingly hold the endportions of said male member against accidental dislodgment from theconnector body.

References Cited UNITED STATES PATENTS 2,690,541 9/1954 Elliott 339-262,857,580 10/1958 Raetsch 339183 3,193,636 7/1965 Daniels 339-182 X 10RICHARD E. MOORE, Primary Examiner US. Cl. X.R.

